Default [Q] problem when copying files from pc to device

hello,

i have a problem when i copy files via usb cable from my pc to my device.

it only occurs if the files are a little larger. i use a custom rom on my g2 and if i want to copy the new version of the rom to my device (181 mb) copying stops just before the end and i have to cancel. Then i have to reconnect my g2. After that i copy the rom zip again and its successfully.
but if i copy gapps (83 mb) its directly copied successfully.

i have the problem on now two custom roms and the problem was not always there only for some time.
and i have tried it with usb debugging enabled and disabled... same problem.

any suggestions to solve the problem?
sorry for my strange english

current devices: LG G2 [D802] | LG G Pad 8.3 [V500]